Not long after I obtained my much-appreciated Jadis Defy 7 Mk. IV amp, the
much-respected reviewer and critic Scot Markwell asked me if I wanted to
hear a preamp that would mate perfectly with the Jadis. The Wyetech Labs
Coral had come to him for review, and he wanted me to hear it before he
shipped it back to the distributor.

Scot also knew that I was hunting for a new preamp. As you can see from my
recent reviews in the Secrets archives, I have been on and remain on a
preamp review kick, learning much in the process. Preamps from Bruce Moore,
BAT, and Audio Note have been reviewed of late; the Manley, Reflection
Audio, new Edge, PS Audio, Messenger, and others are expected for review in
the next number of months. Auditioning and possibly reviewing the Coral, far
more reasonably priced than most of the preamps in this list, seemed an
ideal way to go.

I had already read much commentary about the top-of-the-line Wyetech Opal line
preamplifier ($7,800). Many reviewers of repute consider it one of the
finest under $10,000 preamps on the market. Since Scot and the author of the
one review of the Coral I’ve found on the web both suggested that the
Coral’s sonic signature was remarkably close to the Opal’s, I was eager to
have a listen.

What Wyetech Has to Say

Since releasing their statement piece Opal line preamp four years ago,
Wyetech’s Roger Hebert has experimented with ways to retain the Opal’s
sought after sonic signature, while offering lower price alternatives. He
first issued the Jade line preamplifier ($3,800) two years ago. The Coral
line preamplifier ($2,300) followed in November 2002, with the Pearl line
preamplifier ($5,300) making its début in the fall of 2003.

Roger has done a great job filling Wyetech’s website with information rather
than splash. The initial news release for the Coral states:

“The Coral uses the same precision stepped volume and balance controls
found in the Jade, allowing precise settings and functions not seen before
in a moderately priced preamplifier. Implementing three low noise military
specification NOS dual triode vacuum tubes without the use of feedback, this
preamplifier is compatible with both solid state and tube amplifiers.
Calibrated switch settings allow precise control over all volume and balance
settings. The inputs use relay switching located next to RCA jacks to keep
the signal path as short as possible. Internal jumpers allow for high gain
[12.5 db] or low gain [4.5 db] overall operation.”

As someone who has spent more hours than I wish to recall auditioning upgrades
to the Bruce Moore Companion III preamp, I have become quite familiar with
the difference a resistor, capacitor, or attenuator upgrade makes to
performance. The better the equipment design to begin with, and the better
the overall equipment/cable assemblage, the more one is able to hear the
results of such upgrades.

Upgrades cost money. If a manufacturer upgrades 20 resistors from a brand that
costs $0.20/each to another that costs $2/each, that upgrade alone adds at
least $400 to the retail price. Throw in a more complex circuit, more NOS
tubes, a change of wiring and cabinetry, etc., and you’ve got differences of
many thousands of dollars. And of course, in the case of small operations
such as Wyetech and Bruce Moore, you must figure in the costs of research,
development, repair, and advertising if you are to stay afloat in the
high-end game.

Design and manufacture of the Coral was only made possible after Wyetech
obtained what they term a “lifetime supply of quality military new old stock
[NOS] tubes.” This enabled them to implement “pure triode technology” for a
reasonable price. Wyetech even lists the cost of tube replacement on their
website, something you will rarely find in the high-end arena. Even rarer is
the reality that the tubes are reasonably priced.

Here is some more of Wyetech’s technical description of the Coral, with
grammatical revision by yours truly:

“We've retained the grounded grid configuration which we deem to be the
best possible circuit topology for line level amplification. This circuit,
like the Opal and Jade, maintains an exceptional bandwidth that extends well
beyond 250,000 Hz.

“The 250 Volt DC power supply uses a Pi RC filter network that eliminates all
noise and ripple to below what our test instruments can detect. This was
accomplished by utilizing larger electrolytic reservoir capacitors than
would normally be employed. A 12 Volt DC power supply that consists of a
double Pi RC filter is used to power the tube filaments, thus reducing hum
levels even further.

“We have again avoided using active feedback [regulation] in order to maintain
the speed of the power supply in relation to the extremely fast analog
circuitry.

“We import from Denmark our stepped ELMA volume controls that use 0.1%
precision metal film surface mount resistors that are second best in life
expectancy only to the Shallco military switches used in the Opal. The Coral
uses the same quality volume and balance controls as that found in the Jade
linestage.

The preamp includes two coaxial outputs, which is great for systems with
separate subwoofers, as well as the usual complement of coaxial inputs. I
shall let you be the final judge in terms of design. A sophisticated
appearance is not, IMHO, high on the list of Wyetech priorities. The sound,
however, is another matter.

Setup and Listening

The Coral arrived already broken in. Auditioning the unit was a simple case of
isolating it from vibration, attaching an excellent Elrod EPS-2 Signature
power cord and Nordost Valhalla interconnects, warming it up for an hour
(the same time I give my Jadis), playing Ayre break-in and demagnetizing
tones, and taking a listen. All comparisons were performed with the same
interconnects and speaker cables. Switching back and forth multiple times
during listening evaluations assured me that one preamp was not at a
disadvantage to the other because the cables had been recently shifted.

I did find the preamp’s Mute switch useful. The Coral sometimes makes a little
pop when turned on and off. The sound is soft and doesn’t seem harmful to
one’s speakers. But it’s nicer to turn a preamp on and off in silence.

I had hoped to compare the $2,300 Coral with another tubed preamp, the $4,000
Bruce Moore Companion III. Alas, the Moore was away for yet another upgrade,
this time a change of diodes in the power supply. The only preamp on hand
was my reference preamp of late, the $6000+ solid state Reflection Audio
OM-1 Quantum with an optional battery pack (not used) that raises its price
to close to $8,000. Clearly, putting one against the other is not a fair
comparison. But with judicious listening, it does provide a means of
reference.

My first impression of the Wyetech Coral remains my overriding impression.
This is a beautiful sounding preamp. None of the criticism you read below
should be seen as altering my basic take on the Coral preamp. It is liquid,
smooth, and consistently musical.

My first selection was my old standby, Terry Evans’
“Blues No More” from Puttin’ It Down (JVC-XRCD; also available in SACD).
Terry’s voice was extremely clear. Nonetheless, his voice and the
instruments surrounding it, including Ry Cooder’s guitar, exhibited less
fullness and body than I was accustomed to hearing. The cymbals sounded a
little thinner than usual, and there was less overall color to the
presentation. Edges around the electric guitar were not ideally sharp; there
was a tube-like softness to them that is not a necessary component of tube
gear. The bass, on the other hand, was quite good, the soundstage very
large, open and satisfying, and the entire presentation very smooth. I
didn’t hear everything I was accustomed to hearing, but what I did hear was
a delight.

Then came another old standby, Hilary Hahn’s Brahms Violin Concerto (Sony).
Having just heard Hilary Hahn live in recital last night from Orchestra Row
L, I can attest that this DSD recording is far more truthful than earlier
Sony PCM recordings of Ms. Hahn, regardless of 20- or 24-bit Super Bit
Mapping. I also discovered that Hahn’s violin sounds nowhere as sweet in
person, at least not in Zellerbach Hall (which does have a high frequency
roll-off), as it sounds on virtually every system I’ve played the disc on.
(My system is far less sweet - that’s far more neutral - than most
encountered at CES and HE 2003). But as a recording, the Brahms is very,
very good, and undoubtedly better in single-layer SACD.

Hahn’s orchestral accompaniment sounded quite warm on the bottom; the opening
of the concerto was beautiful. The strings were not as brilliant as I would
like, sounding as though they were heard farther back in the hall rather
than from the best seats in the orchestra. Nor was their attack on
declamatory passages as strong as I was accustomed to hearing. I wanted more
color around Hahn’s violin and a blacker background. But again, the
presentation was so smooth and beautiful that it won me over.

Next came the beginning of Reference Recordings’ Rachmaninoff Symphonic
Dances. The same positives apply. As for negatives, the drum thwaps were
not as startling and clearly delineated as I would have liked, and the
trumpets lacked the cutting edge one experiences live and on the best
systems.

At CES 2004, I came by David Chesky’s Entre Amigos/Among Friends, a new
recording featuring bossa nova vocalist sensation Rosa Passos and bassist
Ron Carter. Back-up, besides Carter’s bass, includes Lula’s guitar solos,
Passos’ guitar, Paulo Braga’s percussion, and Billy Drewes’ tenor sax and
clarinet. I hope to review this recording in the next month or two.

What I missed here were the crispness and ultimate color I hear using the
Reflection Audio preamp. I also heard less breath around Passos’ voice than
with the preamp that costs almost three times as much. But I could really
sense the body of the guitar and its resonance. That is quite an impressive
feat for a preamp that costs $2,300.

Finally, I returned to the disc I dragged from room to room at HE 2003, Karina
Gauvin’s Songs of the Auvergne with chamber orchestra accompaniment (CBC
Records). The drum thwacks on Lou Coucut were not as full as I would have
wished, and I did not hear the usual sharp edge on Gauvin’s soprano. Highs
were not as extended, and there was less color to the instruments than I
would have liked. There was more gray and uniformity of color, and less
brilliance on top than I’m used to hearing on disc and live.

Making Sense of it All

If you’d be good enough to open another window on your browser, please
reference the comparison chart mentioned above:

Note the difference in parts quality in preamps when it comes to resistors,
capacitors, switches, controls, and even the board construction and input
wiring.

I have played with upgrades enough to know something about differences in parts
quality. I don’t know enough to be dangerous, but I do know enough to be
able to state with certainty that when you upgrade resistors, capacitors,
and attenuators, you get:

1. Far greater detail

2. Greater extension at high and low frequencies

3. Blacker background

4. Sharper images (not etched, but more clearly defined)

5. Sharper and clearer attacks

6. More color and three dimensionality because everything stands out more.

7. As an equal consequence of same, more three-dimensionality.

In short, what we are hearing with the Coral is an entry-level preamp whose
design, when taken to its ultimate realization, could well deliver the
exceptional sound attributed to the Opal. Despite its parts shortcomings,
there is an overriding musicality and smoothness to this preamp that makes
it most desirable.

I can also state with surety that few cables are as revealing as Nordost Valhalla. If
there are differences between components, Nordost Valhalla makes them
abundantly clear. The differences I hear between components will be far less
apparent on the more modest systems in which the Coral will most likely find
a place. I would especially think that the Coral would prove a great match
for a solid state amp that lacks warmth and smoothness. Having heard several
iterations of the much-vaunted Audible Illusions Modulus 3A, for example, I
can tell you that as a linestage, the Coral preamp is far more musical and
has far more user-friendly attenuator settings.

Conclusions

Wyetech has done a stunning job with this baby. For an entry-level linestage
preamp, its musicality and smoothness override any shortcomings. Its
deficiencies, which are frequently encountered in preamps in its price
range, are sins of omission rather than of commission. In many systems, the
Coral will prove most desirable. If it’s in your price range, by all means
take advantage of the 30-day trial period and give it a listen. Few if any
preamps I’ve encountered for under $2,500 sound as smooth, musical, and
rewarding.